tbuckley/cabot-search huggingface dataset:
EPCO-09. CHARACTERIZING THE GBM CELLULAR LANDSCAPE BY LARGE-SCALE SINGLE-NUCLEUS RNA-SEQUENCING
Authors: Avishay Spitzer, Masashi Nomura, Luciano Garofano, Kevin Johnson, Djamel Nehar-Belaid, Young Taek Oh, Kevin J Anderson, Ryan D Najac, Lillian Bussema, Frederick Varn, Fulvio D’Angelo, Tamrin Chowdhury, Simona Migliozzi, Jong Bae Park, Luca Ermini, Anna Golebiewska, Simone Niclou, Sunit Das, Sun Ha Paek, Hyo-Eun Moon, Bertrand Mathon, Anna-Luisa Di Stefano, Franck Bielle, Alice Laurenge, Marc Sanson, Shota Tanaka, Nobuhito Saito, Steve Keir, David Ashley, Jason Huse, W K Alfred Yung, Anna Lasorella, Roel Verhaak, Antonio Iavarone, Itay Tirosh, Mario Suva
Journal: Neuro-Oncology (2023)

Abstract Tumor heterogeneity is a well-known hallmark of glioblastoma (GBM). Single-cell RNA-sequencing (scRNA-seq) technologies significantly extended our understanding of GBM intra-tumor heterogeneity. While the landmark scRNA-seq studies were limited by scale, recent technological advances have enabled analyzing increasing numbers of cells. Here, leveraging a large-scale single-nucleus RNA-sequencing (snRNA-seq) dataset containing 457,442 cells (271,444 malignant and 185,995 non-malignant) from 121 IDH-wildtype GBM tumor samples and matching whole-exome/whole-genome sequencing data, we dissected the GBM malignant and tumor microenvironment (TME) compartments with unprecedented resolution and scale. We identified three novel malignant cellular states - Glial progenitor cell-like (GPC-like), Neuron-like and Cilia-like - in addition to the cellular states previously defined in GBM (NPC-like, OPC-like, AC-like and MES-like). Cross-referencing our dataset with published scRNA-seq datasets suggests that GBM states mirror the developmental hierarchy observed in the developing human brain. Functional enrichment analysis demonstrated the heterogeneous nature of pathway and metabolic activities across the spectrum of cellular states. Analysis of the matched DNA-sequencing data revealed novel associations between the occurrence of certain genetic events and the abundance of specific cellular states. Similarly, we dissected the TME and robustly defined cellular states for different TME cell types, underscoring the heterogeneity found also within the TME compartment. Leveraging the large number of samples in our dataset and controlling for intra-tumor cell state frequency exposed three baseline gene expression programs - neuronal activity, glial development and extra-cellular matrix remodeling - termed State-Controlled Profiles (SCPs), that reflect the inter-tumor heterogeneity and are not influenced by the intra-tumor cell state distribution. Integrated analysis of the intra- and inter-tumor heterogeneity components revealed striking associations between certain TME cell types and states, malignant cell states and SCPs, suggesting that an interplay between the TME and malignant cells shapes the frequency of malignant states and baseline expression profile in each tumor.
CSIG-09. RADIOTHERAPY WITH CONCURRENT INHIBITION OF CHEK2 ACTIVATES STING IN GLIOMAS
Authors: Li Chen, Graysen McManus, Victor Arrieta, Kwang-Soo Kim, Karl Habashy, Caylee Silvers, Hinda Najem, Andrew Gould, Atique Ahmed, Rimas Lukas, Amy Heimberger, Catalina Lee-Chang, Adam Sonabend, Crismita Dmello
Journal: Neuro-Oncology (2023)

Abstract Using an in vivo CRISPR screen approach, we demonstrated the contribution of glioma cell intrinsic checkpoint kinase 2 (Chek2) in the evasion of tumor cells from CD8+ T cell recognition. Genetic depletion or pharmacological inhibition of Chek2 with blood-brain-barrier permeable drugs that are being evaluated in clinical trials, in combination with standard of care radiotherapy and PD-1/PD-L1 blockade, led to survival benefit in multiple preclinical glioma models. Moreover, we observed that Chek2 inhibition or depletion is associated with activation of cytosolic DNA-sensing STING pathway in the glioma cells. A positive correlation was identified between STING pathway activity and T cell infiltration in the TCGA glioblastoma dataset. STING activation has been shown to promote robust immune response in glioblastoma. Building upon these results, we evaluated the impact of radiotherapy on Chek2 and STING signaling. After applying 2 Gy radiotherapy, a 20 fold increase of Chek2 activation was observed within the first hour in the in vitro grown glioblastoma patient derived cells, specifically GBM6 and GBM43 cells. Chek2 activation levels returned to the baseline within 6 hours in these cells. However, STING activation was moderate to absent at different time intervals within the first 48 hours post 2 Gy radiotherapy. Interestingly, when the in vitro-grown GBM6 cells were pretreated with Chek1/2 inhibitor prexasertib for 48 hours prior to the 2 Gy radiotherapy exposure, there was 10 fold reduction in the activation of Chek2 as compared to the radiotherapy alone group. Concomitantly, a 2-fold increase in the activation of STING was noted for up to 48 h in the pretreated group, as compared to the radiotherapy alone group. Our in vitro findings suggest an inverse relationship between the activation of Chek2 and STING. In conclusion, radiotherapy with concurrent inhibition of Chek2 offers a novel therapeutic combination to modulate STING activation in gliomas.
CTNI-27. <i>TRIAL IN PROGRESS</i> A PHASE 2 STUDY OF BPM 31510 (AN OXIDIZED COQ10-LIPID CONJUGATE NANODISPERSION) WITH VITAMIN K AND STANDARD CHEMORADIATION IN NEWLY DIAGNOSED GLIOBLASTOMA
Authors: Brian Stocksdale, Sophie Bertrand, Eleanor Villanueva, Lewis Naya, Donna Molaie, Arianne Lyng, Brian Berman, Vivek Vishnudas, Michael Kiebish, Stephane Gesta, Niven Narain, Lawrence Recht, Seema Nagpal
Journal: Neuro-Oncology (2023)

Abstract INTRODUCTION: BPM 31510 is a novel drug-lipid conjugate nanodispersion that significantly increases the bioavailability of ubidecarenone (oxidized CoQ10). Supraphysiological concentrations of CoQ10 have been shown to have a paradoxical pro-oxidant effect on a variety of malignant cells while not altering the metabolic phenotype in normal cells. Glioblastoma multiforme (GBM) is a metabolically active cancer that is reliant on mechanisms of redox homeostasis to avert reactive oxygen species (ROS)-triggered apoptosis. This trial investigates whether this susceptibility of GBM metabolism may be effectively targeted by the potentially synergistic combination of BPM 31510 and standard-of-care radiotherapy, a known producer of ROS. Early-phase trials of BPM 31510 have shown a favorable safety profile with primarily hepatotoxicity and coagulopathy, the latter of which is mitigated by co-administration of Vitamin K. TRIAL DESIGN: BPM 31510IV-11 (NCT04752813) is a single-arm multicenter phase 2 study of BPM 31510 + Vitamin K1 in combination with standard chemoradiation for newly diagnosed GBM. Eligible patients have GBM with no prior therapy, and those with recent hemorrhage, coagulopathy, or who require anticoagulation are excluded. BPM 31510 starts 2-4 weeks after biopsy or resection initially as monotherapy for 2 weeks followed by an additional 6 weeks in combination with temozolomide-based chemoradiation. To assess safety of BPM 31510 with concomitant chemoradiotherapy, this study begins with a dose confirmation phase and allows for one dose reduction in the event of a DLT. The starting dose of BPM 31510 is 110 mg/kg administered as a continuous infusion over 96-hours weekly. The primary endpoint is 6-month progression-free survival (PFS6) by RANO criteria. Secondary endpoints include overall survival and safety. Approximately 50 patients will be enrolled for 90% power in rejecting the null hypothesis of PFS6 ≤ 30%. The study is enrolling at two US sites with a third opening soon.
CTNI-35. A RANDOMIZED, CONTROLLED TRIAL OF BERUBICIN VS. LOMUSTINE AFTER FIRST-LINE THERAPY FOR GLIOBLASTOMA MULTIFORME (GBM): INTERIM RESULTS OF A PRE-PLANNED ANALYSIS OF OVERALL SURVIVAL (OS)
Authors: Sandra Silberman, Zena Muzyczenko, Sigmund Hsu
Journal: Neuro-Oncology (2023)

Abstract Berubicin is an analog of doxorubicin (Dox) that appears to cross the BBB with significant central nervous system (CNS) uptake. RESULTS: of a Phase 1 dose-escalation study with 25 patients evaluable for efficacy showed 1 complete response (14+ years), 1 partial response durable for 12 weeks, and 9 patients with stable disease for a clinical benefit rate of 44%. Our current, potentially pivotal trial for patients with recurrent GBM after first-line therapy is enrolling in the US and Europe. It is unique in that all patients must be Grade 4 IDH WT, classifying these tumors as a poorer prognostic population than Grade 4 IDH mutated. Patients are randomized in a 2:1 design of Berubicin:Lomustine and stratified by MGMT methylation status. The primary endpoint is OS. Data has been presented showing that Berubicin and Lomustine arms are balanced with respect to MGMT status and demographics, with relatively comparable safety profiles (SNO Annual Meeting 2022 Abstract #383142). A pre-planned non-binding futlity analysis of the primary endpoint, OS, is being evaluated when the trial reaches ~30% of expected events (44 events). The interim analysis will be performed by an independent statistician under the supervision of the Data Safety Monitoring Board (DSMB). The futility analysis will be based on the conditional power that the trial will be positive (e.g., statistically significant difference between treatment groups’ OS). If the conditional power is &amp;lt;10% then the DSMB may recommend to end the study; otherwise the study will continue as it is currently planned. The review will also include safety and secondary efficacy endpoint summaries. RESULTS: of this interim analysis will be available for the SNO annual meeting and an evaluation of its outcome will be performed, with conclusions and recommendations for the further development of Berubicin as a therapeutic option for patients with recurrent GBM.
CSIG-27. FLUID SHEAR STRESS ACTIVATES A MECHANO-METASTATIC CASCADE TO PROMOTE MEDULLOBLASTOMA METASTASIS
Authors: Hyun-Kee Min, Hongyu Zhao, Xi Huang
Journal: Neuro-Oncology (2023)

Abstract Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Dissemination of MB cells into cerebrospinal fluid (CSF) and blood initiates metastasis in the central nervous system, which significantly worsens patient prognosis. Disseminated MB cells survive the nutrient-deprived CSF environment and are subjected to fluid shear stress (FSS) by CSF flow. Whether and how FSS contributes to MB metastasis is completely unknown. We computationally simulated FSS dynamics in MB patients using MRI-informed CSF flow models. Based on CSF flow rates and force magnitudes in patients, we engineered two FSS application systems: (1) an orbital shaker system that applies FSS to large populations of cells, and (2) a microfluidic system compatible with live-cell and high-resolution imaging. By applying physiologically relevant FSS to MB cells, we discovered that FSS-treated MB cells metastasize more frequently and form larger metastatic tumors along the spinal cords of mice. Mechanistically, FSS induces actomyosin contraction, which promotes cell clustering, glucose transporter 1 (GLUT1) localization at the cell surface, and GLUT1-dependent glucose uptake. FSS elevates intracellular calcium through mechanosensitive ion channel PIEZO2, which is required for FSS-induced actomyosin contraction, cell clustering, and GLUT1 activity. Genetically perturbing PIEZO2 or pharmacologically inhibiting GLUT1 robustly suppresses MB metastasis in mice. Collectively, we discover that MB cells perceive FSS, define an FSS-activated mechano-metastatic cascade, and demonstrate that this cascade is clinically targetable to mitigate MB metastasis.
EXTH-07. NEOADJUVANT PD1 BLOCKADE ALTERS THE TUMOR MICROENVIRONMENT POST-SURGERY IN A PRECLINICAL MODEL OF RECURRENT GLIOBLASTOMA
Authors: Lan Hoang-Minh, Duane Mitchell, Kelena Klippel, Changlin Yang, Vrunda Trivedi, Bently Doonan, Christina Von Roemeling, Oleg Yegorov, Akshayaa Sriharan, Connor Francis, David Shin, Aida Karachi, Matthew Sarkisian
Journal: Neuro-Oncology (2023)

Abstract SIGNIFICANCE Clinical trials investigating neoadjuvant immunotherapy in recurrent glioblastoma patients have shown promising results. In this study, we aimed to assess the impact of neoadjuvant PD1 blockade on the tumor microenvironment after surgery using a relevant murine model of recurrent glioblastoma. OBJECTIVE Our objective was to investigate the effects of neoadjuvant PD1 inhibition on mouse survival and analyze the transcriptome and spatial genomic changes within the intratumoral immune populations following surgery. We compared these changes with those observed in adjuvant anti-PD1 treatment. RESULTS Through our established murine resection model of recurrent KR158 glioblastoma, we demonstrated that neoadjuvant PD1 inhibition prior to tumor debulking significantly improved mouse survival compared to adjuvant treatment. Transcriptome and spatial genomic analyses revealed notable alterations in immune exhaustion and activation pathway genes after neoadjuvant anti-PD1 treatment, distinguishing it from adjuvant anti-PD1 treatment. RNA and protein analyses indicated upregulation of various pathways, including PI3K/AKT, NOTCH, NK cell, MAPK, NF-kB, type II interferon, and TNF, in the neoadjuvant treatment group compared to the adjuvant anti-PD1 treatment group. Single-cell RNA sequencing analyses further revealed an increased proportion of CD8 T, NKT, and NK cells, accompanied by a decreased percentage of CD4 T cells in the neoadjuvant group. Importantly, we observed a significant enhancement in the interaction strength between CD8 T cells and all other immune cells in the neoadjuvant group compared to the adjuvant treatment group. CONCLUSIONS Our findings demonstrate distinct differences in immune cell populations and gene expression profiles between neoadjuvant and adjuvant anti-PD1 therapies in our murine recurrent glioblastoma resection model. These insights provide valuable understanding of the potential mechanisms underlying the divergent efficacy of neoadjuvant and adjuvant anti-PD1 therapies.
DDDR-32. EVALUATING THE THERAPEUTIC EFFECTS OF SMALL MOLECULE INHIBITORS OF CDK4/6 AND FAK IN PRECLINICAL MENINGIOMA MODELS
Authors: Nazanin Ijad, Katie Waller, Naema Nayyar, Erika Yamazawa, Elizabeth Summers, Christian Migliarese, Evanthia Galanis, Jann Sarkaria, Rachael Vaubel, Hiroaki Wakimoto, Priscilla Brastianos
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND New therapies are needed for meningioma since treatment options are limited once patients have exhausted surgery and radiation. FAK, CDK4/6 and RAF/MEK represent potential targets because of synthetic lethality with NF2, loss of CDKN2A, and activation of MAPK signaling pathway in meningioma, respectively. The objective of this study was to evaluate the efficacy of targeting FAK, CDK4/6 and RAF/MEK as monotherapies and combination therapies in traditional and patient-derived cell lines and xenografts. METHODS In vitro, cell viability and proliferation assays were used to test abemaciclib (CDK4/6 inhibitor), defactinib (FAK inhibitor) and VS-6766 (RAF/MEK inhibitor) as monotherapy and in combination. To better recapitulate the meningioma microenvironment, targeted agents were evaluated with Matrigel, an artificial extracellular matrix. The efficacy of VS-4718 (in vivo formulation of defactinib) and abemaciclib were evaluated in a subcutaneous IOMM-lee meningioma model (having CDKN2A loss) in nude mice. Furthermore, we are establishing cell cultures and patient-derived cell and xenograft (PDX) models using freshly-resected tissue from patients with recurrent or high-grade (WHO grade 2-3) meningiomas. RESULTS In vitro evaluation identified the combination of defactinib with abemaciclib resulted in a synergistic decrease in cell viability relative to each monotherapy alone, while the combination of defactinib+VS-6766 was not beneficial. The presence of Matrigel enhanced the sensitivity of all three agents. In vivo, we observed improved survival in mice treated with abemaciclib vs control (45 days vs 26 days; p=0.03), as well as combination of VS-4718 + abemaciclib vs control (44 days vs 26 days; p=0.04, Gehan-Breslow-Wilcoxon test). We did not observe survival extension with VS-4718 monotherapy. Lastly, we successfully established an orthotopic meningioma PDX using a WHO Grade 3 tumor for evaluation of novel therapies in meningioma. CONCLUSION Abemaciclib showed promising efficacy in preclinical meningioma xenografts with CDKN2A loss. Studies to evaluate these therapies in other orthotopic models are underway.
CTNI-40. A MULTICENTER, RETROSPECTIVE ANALYSIS OF PROGNOSTIC FACTORS IN INTRACRANIAL H3 K27M-MUTANT DIFFUSE MIDLINE GLIOMA IN ADULTS
Authors: Alice Ryba, Zeynep Özdemir, Nitzan Nissimov, Lisa Hönikl, Nicolas Noel Neidert, Martin Jakobs, Darius Kalasauskas, Aleksandrs Krigers, Christian Freyschlag, Florian Ringel, Philip Dao Trong, Dieter Henrik Heiland, Jens Gempt, Julia Onken, Eric Suero Molina, Manfred Westphal, Ulrich Schüller, Malte Mohme
Journal: Neuro-Oncology (2023)

Abstract H3 K27M-mutant glioma were first described as a new grade IV entity in the 2016 WHO classification. Current studies have focused on its common pediatric appearance, increasing the need to better understand this entity in adults. Here we report a multicentric, retrospective analysis of 70 diffuse midline glioma in adults. We included molecularly confirmed H3K27M-mutant glioma in patients &amp;gt;18 years of age between 2015-2022. Clinical-, radiological- and surgical features were analyzed. Univariate and multivariate analyses were then performed to identify prognostic factors. The study was approved by the ethics committee (PV4904). Overall, 70 patients were identified, with a mean age of 36.13 years at the initial diagnosis. Median overall survival was 13.62 + 14 months. H3K27M-mutated glioma showed a midline involvement in 61.4%. Clinically, obstructive hydrocephalus was observed in almost half of the patients (46.3%). Gross total resection (GTR) was achieved in 14.5% of all patients. 30.4% had a subtotal resection (STR), and 55.1% received a biopsy. Intraoperative cryo-section resulted in low-grade glioma in 25%, high-grade glioma in 63.9% and no tumor in 11.1%. Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location site in the mesencephalon/metencephalon showed a significantly longer survival (8.3 vs. 16.2 months, p = 0.009). Preoperative Karnofsky Performance Score (KPS) below 80 showed a reduced OS (6 vs. 11.24 months, p = 0.03). Patients, who received resection (GTR/STR) showed no significant survival benefit compared with biopsied patients (9.6 vs. 8 months, p = 0.4817). The present study describes surgical features of DMG with H3K27M mutation in one of the most extensive multicentric studies to date in adult patients. Our data show that location and preoperative KPS impact OS significantly in DMG. Furthermore, in our dataset resection of K27M-mutated glioma provided no significant survival benefit compared with biopsy.
EPCO-21. IDENTIFYING FACTORS THAT PREDICT GENETIC PREDISPOSITION TO BRAIN TUMOR FORMATION
Authors: John Lee, Arushi Tripathy, Tannaz Guivatchian, Erika Koeppe, Elena Stoffel, Wajd Al-Holou
Journal: Neuro-Oncology (2023)

Abstract INTRODUCTION Increasing evidence suggests that glioma formation may have a greater hereditary component than initially thought. Identification of individuals with a genetic predisposition is critical for appropriate monitoring and treatment. OBJECTIVE To analyze the personal and family histories of patients with intrinsic brain tumors seen in a cancer genetics clinic to inform referral practices. METHODS A prospective database of cancer genetics data from a large multidisciplinary cancer genetics clinic was queried for brain tumors from 2007-2023. Genetic test results, age of brain cancer diagnosis, number/types of distinct cancers, oncologic family history, and personal and family history of cancer syndromes were recorded. Fisher’s exact tests and ANOVA were used for analysis. RESULTS Sixty-five patients with intrinsic brain tumors, which included 53 high and low grade gliomas, were identified. There were 33 males; the mean age of diagnosis was 34.6±23.4. Fifty-three (81.5%) had genetic testing performed. Of these, 19 (35.8%) were found to have germline pathogenic variants (PV), 10 (18.9%) had variants of unknown significance (VUS), and 24 (45.3%) were found to have no mutations. Patients with PVs were younger than patients with normal genetic screening (28.1 vs 41.5 years, p= 0.06), and patients with either PV or VUS were significantly younger (p= 0.04) than patients with normal screening. Regarding personal cancer history, patients with and without PVs had a similar history of personal cancers (p= 0.20). Regarding family history, only 1 patient with PV had a family history of brain cancer compared to 15 in patients with negative testing (5.3% vs 44.1%, p= 0.004). CONCLUSIONS Only younger age at presentation was identified as a predictor of a PV or VUS. A lack of personal/family history of cancer does not preclude a genetic predisposition to cancer. We recommend that younger patients with intrinsic brain tumors should be referred for genetic testing.
IMMU-05. CD8 IMMUNOPET IMAGING IS ABLE TO MONITOR THE IMMUNE RESPONSE SENSITIVELY AND SPECIFICALLY IN GBM PATIENTS FOLLOWING NEOADJUVANT CHECKPOINT BLOCKADE IMMUNOTHERAPY
Authors: Robert Prins, Arda Konik, Lu Sun, Lauren Markus, Gilbert Herrera, Lei Qin, Richard Everson, Eudocia Lee, David Reardon, Hina Shah, Raymond Y Huang, Benjamin Ellingson, Timothy Cloughesy, Patrick Wen, Annick D Van den Abbeele
Journal: Neuro-Oncology (2023)

Abstract The sensitive and specific evaluation of treatment response in glioblastoma (GBM) patients following immunotherapy is a clinical dilemma. Traditional MRI assessments to visualize and quantify intracranial tumor burden following immunotherapy cannot reliably differentiate tumor progression and pseudo progression remains a complicating factor. In this study, we provide an early report on the use of an investigational new functional imaging PET tracer (CD8 ImmunoPET, 89Zr-crefmirlimab berdoxam, ImaginAb) prior to and immediately following neoadjuvant checkpoint blockade immunotherapy in five patients with recurrent GBM. Tumor samples were collected from each patient at surgery following a two-week neoadjuvant checkpoint blockade to assess gene expression changes and TIL density. We then evaluated how such tumor measurements correlated with PET metrics obtained at baseline and within 2 weeks after treatment initiation which included standardized uptake values (SUVmax, SUVpeak, and SUVmean), and two proposed new metrics indicating the Volume of Immunometabolism (VIM), and the Total Lesion or Lymph nodes’ T cells called TLTc (TLTc = VI x SUVmean) in the tumor bed and lymph node basins (neck, axillae, and inguinal regions). CD8 ImmunoPET demonstrated tracer uptake in the intracranial tumor at both time points, as well as specific physiologic uptake in lymph node basins, spleen, liver, and bone marrow. Neoadjuvant checkpoint blockade with PD-1 +/- CTLA-4 mAb (Nivolumab, Ipilimumab, BMS) at 2 weeks induced variable changes in SUV, but in four of the five initial patients studied in this clinical trial, an increase in VI and TLTc was observed within the tumor bed. Tracer uptake was associated with elevated T cell infiltration into the tumor bed and gene expression changes indicative of interferon signaling and immune cells in these same patients. Our early findings identify a noninvasive functional imaging platform to evaluate the immunometabolism secondary to T cell infiltration and/or activation changes following immunotherapy in GBM patients.